1. Field of the Invention
The present invention relates to the field of electronic aerosol generating devices, and more particularly to a dual air-chamber fully sealed piezoelectric nebulization module packaged into a fully sealed casing and having two independent air chambers to assure the nebulization and protection effects.
2. Description of the Related Art
In general, a conventional nebulization module comprises a piezoelectric actuator (or a vibratory element) made of a piezoelectric actuating material, an aerosolizing element and a structural plate. After the nebulization module is in contact with a liquid to be atomized, the piezoelectric actuator drives and compresses the liquid to be atomized to spray the liquid to be atomized out from a small spray hole of the aerosolizing element. However, the piezoelectric actuator is generally made of a material containing heavy metals (such as lead) which may be reacted with the liquid and released, so that heavy metals may be released from the piezoelectric actuator to contaminate the liquid during the use of the conventional nebulization module due to its direct contact with the liquid to be atomized. As a result, the contaminated liquid is sprayed out from the atomizing device, and inhaled or touched by users. In addition, the piezoelectric actuator, the aerosolizing element and the structural plate are connected by soldering or curing structure adhesives. Regardless of the aforementioned ways of connecting the components, when a liquid (particularly medical liquids containing chlorine ions, strong oxidizers, or corrosive ingredients) is atomized, chemical reaction may occur to corrode or damage the nebulization module or reduce the structural adhesion; this is due to solder material or curing structure adhesive on a joint surface is contacted with the liquid. As a result, the overall structure of the atomizing device may be decomposed, and service life may be affected adversely.
To overcome the aforementioned problem, another conventional piezoelectric nebulization module further uses a flexible member (such as O-ring) as an isolating mechanism or uses the flexible member together with other component to achieve the isolation effect and reduce the possibility of the liquid to be contacted with the piezoelectric actuator.
With reference to FIG. 1 for a schematic view of an apparatus made by a method as disclosed in U.S. Pat. No. 7,771,642 B2 entitled “Method of making an apparatus for providing aerosol for medical treatment”, a sealing element 1 made of a rubber or a flexible member is used and attached completely to an aerosolizing element 11, a vibratory element 12, an actuating element 13 (or actuator), and the sealing element 1 is provided for resisting and isolating water from the vibratory element 12 to prevent the apparatus from being corroded or damaged by fluids. However, such conventional atomizing device has the design of attaching the sealing element 1 completely onto the vibratory element 12, so that the area for vibrating the vibratory element 12 is limited. In the meantime, such design also causes the vibration energy produced by the vibratory element 12 is absorbed or inhibited by the sealing element 1 which is made of rubber or flexible member, so that the overall nebulization performance is reduced.
With reference to FIG. 2A for an aerosol generating means for inhalation therapy devices as disclosed in U.S. Pat. No. 7,891,352 B2, the encapsulating means 2 comes with two flexible sealing lips 21 and an oscillatable assembly 3 installed and fixed inside the encapsulating means, wherein the encapsulating means 2 and the flexible sealing lip 21 constitute a partition for providing a space for the high-frequency vibration of the oscillatable assembly and isolating the liquid to be atomized from a direct contact with the oscillatable assembly, and the oscillatable assembly comprises a membrane 31, an annular oscillation generator 32 and an annular substrate 33. Although such atomizing device forms a partition with the flexible sealing lips 21 and the encapsulating means to provide a circular moving space for the oscillation of the oscillation generator 32 instead of using the sealing element 1 made of a flexible member, yet such atomizing device still has the following drawbacks in use.
With reference to FIG. 2B for a schematic view of the vibration wave transmission during an operation as disclosed in U.S. Pat. No. 7,891,352 B2, both fixing and sealing functions of the oscillatable assembly rely on the two flexible sealing lips 21, so that if no substantial support action is applied, the oscillatable assembly may fall off or leak during use. When the oscillatable assembly atomizes water vapor by high-frequency vibrations, the substantial clamping force must be applied to the oscillatable assembly in order to prevent it from falling out or leaking, and thus inhibiting the oscillation, reducing the vibration energy and affecting the nebulization performance adversely.
After the two flexible sealing lips 21 are bent by force, structural cracks may be formed at the junction of the oscillatable assembly and the encapsulating means 2, and dirt or contaminants may be accumulated easily to contaminate the liquid to be atomized or the spray mist. In addition, the encapsulating means 2 and the two flexible sealing lips 21 constitute a single-space design for isolating external liquid to be atomized, so that if the flexible sealing lips 21 are elastically fatigue and the sealing effect is insufficient or leakage is caused by long-term corrosion, the liquid to be atomized will flow into the space directly to corrode the annular oscillation generator 32, so as to contaminate the liquid to be atomized or damage the annular oscillation generator 320.
In addition, the two flexible sealing lips 21 are installed on the annular substrate 33 or the annular oscillation generator 32 of the oscillatable assembly 3, and the curing structure adhesive or solder material at the joint surface of the membrane 31 and the annular substrate 33 or the annular oscillation generator 32 is exposed to the outside. After, so that the solder material or curing structure adhesive at the joint surface is contacted with the liquid to have a chemical reaction, the overall structure of the atomizing device may be decomposed by corrosion and the structural adhesion may be reduced, and thus affecting the service life.
In summation, the conventional nebulization devices provide different isolating methods, but still fail to provide a vibration inhibition effect for the atomizing device; they also fail to isolate liquid or medical solution from contacting with the joint of the atomizing device or the piezoelectric actuator. Obviously, the conventional nebulization devices require further improvements.